Electricity

The three main hazards are contact with the live parts, fire and explosion. Each year about 1000 accidents at work involving shocks and burn are reported and about 30 of these are fatal. Fires started by poor electrical installations cause many other deaths and injuries. Explosions are caused by electrical apparatus or static electricity igniting flammable vapours or dust.
Assess the risks from your use of electricity and use the precautions described in this section to control them. Remember normal main voltage (240 volts AC) can kill. The risks are greater when electricity is used in harsh conditions, e.g. portable electrical equipments used outdoors, or in cramped spaces with a lot of earthed metal work, e.g. inside a boiler or bin.

Reduce the Voltage

1. lighting can run at 12 or 25 volts
2. portable tools can run at 110 volts from any isolating transformer.

Provide a Safety Device

1. a residual current device can act as a safety trip when there is a fault. This is not a substitute for a proper installation

A Safe Installation

1. provide enough socket outlets, if necessary, by using a multi-plug socket block overloading sockets by using adapters can cause fire
2. fuses, circuit-breakers and other devices must be correctly rated for the circuit they protect.
3. there must be a isolator or a switch near each fixed machine to cut off power in case of emergency.
4. the main switches must be readily accessible and clearly identified.

Insulation, Protection and Earthing

1. power cables to machine must be insulated, e.g. sheathed and armoured or installed in conduit. Earth connections must be in a good condition.
2. if you use a flexible cable you must always use a proper plug with a flex firmly clamped to stop the wires ( particularly the earth) pulling out of the terminals.
3. some tools are double insulated for extra protection and these have only two wires (neutral and live). Make sure you connect them properly.
4. replace frayed and damaged cables completely. Join lengths in good condition only by using proper connectors or cable couplers.
5. protect light bulbs or other items which may be easily damaged in use.
6. you must use special protection where electrical equipment is used in flammable or dusty environments. Low voltage equipment (e.g. 12 volts) gives no protection against igniting flammable vapours. To choose the correct equipment you may need a expert advice.
7. when carrying or pouring organic powders (e.g. flour, tea dust) or flammable liquids, use closed metal containers and make sure all metal work is bonded and earthed.
8. for jobs like electrostatic paint spraying, make sure that both the work and anyone in he area are adequately earthed, e.g. by getting the operator and others to wear antistatic foot wear, otherwise electrostatic charges can build up which can cause a spark.

Safe Operation

1. you must not allow anyone to work on or near live equipments, unless it is unavoidable and special precautions are taken. Ask your inspector for advice.
Check that:
2. suspect or faulty equipment is taken out of use, labeled “Do not use” and kept secure until checked by a competent person.
3. tools and power sockets are switched off before plugging in or unplugging.
4. appliances are unplugged before cleaning or making adjustments.

Overhead Electric Lines

1. Contact with overhead electric lines accounts for half of the fatal electrical accidents each year. Electricity can flash over from overhead power lines even though plant and equipment may not touch them. Don’t work under them where any equipment e.g. ladders, a crane jib, a tipper lorry body , a scaffold pole could come within 9 m of a power line without seeking advice.

Maintenance

1. all electrical equipment, wiring installations, generators or battery sets and everything connected to them, must be maintained to prevent danger. This means carrying out checks and inspections and repairing and testing as necessary – how often will depend on the equipment you use and where you use it.
2. you must prevent access to electrical danger by keeping isolator and fuse box covers closed and (if possible) locked, with the key held by responsible person.
3. anyone carrying out electrical work must be competent to do it safely. This may mean bringing in outside contractors; if so make sure they belong to a body which checks their work.
4. check the residual current circuit-breakers work by operating the test button regularly.
5. make sure that special maintenance requirements of waterproof or explosion protected equipment have been written down and that someone is made responsible for carrying out the work without damaging the protection.

Underground Cables

1. consult your electricity company if you are likely to be digging near buried cables – they should know where these are.
2. always assume cables will be present when digging holes in streets, pavement or near buildings. If you have to work near services, use service plans, locators and safe digging practice to avoid danger.